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Screening holds key to beating cancer
Whether they occur in the lung, large bowel
or prostate, cancers diagnosed
early offer far better survival rates. TAN SU YEN reports
CANCER should be
associated with survival, not death - that was the
take-home message of a campaign launched by the National Cancer
Centre
Singapore in June this year. Much of the progress in cancer
treatment lies
in the work of identifying cancer precursors in the early days
of the
disease and, sometimes, even before the onset of malignancy.
Screening is
key to winning the fight against cancers of the large bowel,
the prostate
and the lung - three of the most common cancers that affect
men in
Singapore.
Large bowel cancer
 Large bowel
or colorectal cancer refers to cancers in the 80 cm long large
intestine. Eight-five per cent of all colorectal cancers
arise from polyps
that could take up to five years to 10 years to transform
into malignancy.
However, most patients don't realise because these tumours
grow silently.
Says Dr Heah Sieu Min, consultant colorectal specialist surgeon,
Pacific
Colorectal Centre in Paragon, a member of Pacific Healthcare:
'Many people
think that there is no need to get themselves screened for
bowel cancer if
they don't have any symptoms. What they don't realise is
that small
polyps, and those that progress to become cancerous, often
show no
symptoms whatsoever. Even at Stage 1, patients may experience
no symptoms
at all - no bleeding or obstruction, no pain in the abdomen
and no change
in bowel habits simply because the tumour is too small to
produce
symptoms. Often, by the time patients experience symptoms,
the cancer has
already progressed to Stage 2 or 3.'
Protocols recommend that screening start at
50. However, colorectal
specialists note a sharp rise in large bowel cancers in
the general
population at 50, suggesting a need for earlier screening.
Says Dr Heah:
'The idea is to be screened when you have no symptoms,
so that if there is
a tumour it is likely to be at an early Stage 1. If there
are polyps, we
can remove them concurrently, thus arresting their progression
into
cancers.'
Currently, the screening method of choice is
a colonoscopy, a 15-minute
procedure performed under intravenous sedation. Says
Dr Heah: 'A
colonoscopy is the most accurate form of scoping because
it involves
direct visualisation of the innermost lining of the large
bowel where
polyps and cancers originate. It is also the only investigation
that
allows biopsy of the tissues (mucosa). We can also remove
polyps through
colonoscopy performed concurrently so that it may be
therapeutic as well.
When the colon is clean the accuracy should approach
100 per cent.'
Screening is recommended in the 40s for those
with symptoms like rectal
bleeding, mucus, bloating and abdominal pain as well
as changes in bowel
habits. Early screening is also recommended for those
with a family
history of bowel cancer. About 25 per cent of colorectal
cancers occur in
people with a family history of bowel cancer. Among those
with a family
history, two groups need to be monitored very closely.
The first are those
with what is known as familial adenomatous polyposis
or FAP, and the
second are those with a condition known as hereditary
non-polyposis
colorectal cancer or HNPCC.
Those with a family history of FAP have a one
in two chance of developing
the disease that presents as more than 100 polyps developing
in the colon,
usually beginning in their teens. If untreated, people
with FAP tend to
develop colon cancer in their 30s and invariably die
in their 40s.
A landmark event in managing those with FAP has been
the development of
the Protein Truncation Test or PTT, a blood test to identify
a
protein-truncated gene in families with FAP. Once the
protein-truncated
gene is identified in a patient, their children and siblings
are tested
accordingly. If they are positive for the gene, then
monitoring for polyps
and early surgery to remove the entire large bowel in
the patient's 30s
will be necessary to prevent inevitable cancer development
and consequent
death.
Bowel cancers tend to occur de nouveau in those
with a family history of
HNPCC - that is, the cancer tends to bypass the polyp
stage. Says Dr Heah:
'As HNPCC is passed from one generation to another, and
occurs in
association with other cancers like uterine cancer in
women and urological
cancers in men, doctors tend to scope those with HNPCC
when they are
younger (usually 10 years younger than the age when the
affected relative
is diagnosed with cancer) and to do it at shorter intervals,
for example,
every two years rather than three to five-yearly.'
Bowel cancers that are caught early tend to have very
encouraging survival
rates. Stage 1 cancers have a five-year survival rate
of 95 per cent while
Stage 2 cancers have a survival rate of 75 per cent.
Survival rates for
Stage 3 range from 35-60 per cent.
Prostate cancer
 The prostate is a walnut-size gland that produces part
of the seminal
fluid that together with sperms makes up semen. The
fluid from the
prostate actually neutralises the vagina, preventing
the sperms from
getting knocked out before they reach the eggs. Apart
from that, the
prostate's main claim to fame is that the urethra runs
through it. Says Dr
Damian Png, consultant urologist, MD
Specialist Healthcare,
a member of
Pacific Healthcare: 'That is why, in most men, problems
with the prostate
become magnified because it affects the urinary flow.'
Prostate cancer is Singapore's fastest-rising
cancer - it is now No 4
among cancers that affect men here. The good news is
that these days most
cancers are caught early, an encouraging reversal of
the situation in the
past. Says Dr Png: 'In the past, 70 per cent of prostate
cancers that we
picked up were in their late stages and had spread
to the bones and the
urinary system presenting with symptoms like bleeding.
Today, 70 per cent
of the cancers we detect are early cancers and that
is because we
routinely screen people who come to us for problems
like prostate
enlargement.'
Prostate enlargement is a very common problem,
affecting up to 90 per cent
of men. However, it should not be confused with prostate
cancer. Dr Png
explains: 'When the enlargement is significant, two
sets of symptoms
emerge. The patient may have a greater urge waking
up at night to pee, and
this urge may arise more frequently. Secondly, after
they pee, they find
that there is pee left behind. It also takes a longer
time to start the
flow because it is slower and with some dribbling.
These symptoms point to
an obstruction due to prostate enlargement. We must
bear in mind that
prostate cancer can occur in such a situation, but
this is not always the
case. Just because you have urinary tract symptoms
does not mean you have
prostate cancer. But when there are symptoms, what
we do is to check for
cancer first and then treat the symptoms of prostate
enlargement.'
Screening is usually recommended for men aged
50 and above. Those with
symptoms or a family history of prostate cancer should
be screened in
their 40s. Treatment for prostate cancer usually involves
a combination of
surgery and radiotherapy, which could be 'conformal'
meaning it conforms
to the area of the prostate, reducing the side-effects
to the
surroundings, or 'modulated' to allow for modulations
in the dose to
respond to the particular positioning of the tumour.
As prostate cancer is one of the slowest growing cancers
around, early
detection and treatment can lead to excellent outcomes.
Adds Dr Png: 'With
prostate cancer, we are looking at 15-year survival
rates. At Stage 1,
survival rates are 95 per cent, while survival rates
for Stage 2 are 70-80
per cent. Even at Stage 3 and 4, we can now sustain
patients for two to
seven years with a fairly good quality of life.'
Lung cancer
According to the Singapore Cancer Registry, lung cancer
has been the
leading cause of death here since 1968. Until as recently
as five years
ago, there were major roadblocks in the treatment and
diagnosis of lung
cancer. But all that has changed, as Dr Hui Kok Pheng,
respiratory
specialist & intensivist, Pacific
Healthcare Specialist Centre, explains: 'The prospects
of lung cancer are brighter with earlier
detection and the
availability of new, effective anti-cancer drugs that
can help patients in
the later stage of the disease.'
In the past, lung X-rays could only
pick up late-stage cancers. The
introduction of CT scans allowed physicians to detect
lung cancer as early
as Stage 1. One of the most significant developments
in the detection of
lung cancer recently has been the development of
a new technique of
bronchoscopy, the Auto Fluorescence Bronchoscopy
or AFB.
'AFB is a procedure which employs a small, fibre
optic scope to examine
the airways of the lung. It can detect very early,
abnormal lesions that
have the thickness of a few layers of cell. These
lesions are at a
pre-cancerous stage that is not detectable even by
CT scan. In patients
already diagnosed with lung cancer, the AFB can detect
a recurrence or the
emergence of a second cancer,' Dr Hui points out.
Sculpting a new lease of life
Breast cancer survivors can look
forward to living life to the fullest
with breast reconstruction options that are safe and increasingly natural.
TAN SU YEN reports
THERE is good
reason for the sustained public
education campaign
on breast
cancer - it is the most common
cancer affecting Singapore women.
Every
year, about 1,100 new cases of
breast cancer are diagnosed, translating
into three women being diagnosed
with breast cancer every day.
Dr Ann Tan, consultant obstetrician
and gynaecologist, Women & Fetal
Centre, a member of Pacific
Healthcare, says: 'Breast cancer
is three
times more common than all the
gynaecological malignancies put
together.
It is estimated that less than
10 per cent of breast cancers are
due to
inherited causes. The rest are
due to environmental causes.'
Prevention
is a key tenet of breast cancer
awareness.
Dr Tan, who is
president of the Association
of Women Doctors Singapore,
says: 'Every
woman has to make an individual
choice. Maintain a normal weight,
eat a
diet rich in fruit and vegetables,
exercise regularly, limit your
alcohol
intake and quit smoking. Lowering
your risk of breast cancer will
also
make you less susceptible to heart
and bone disease.'
There are other
reasons for breast cancer patients
to be optimistic - thanks to early
detection and more aggressive treatment,
more women
are
surviving breast cancer today.
A patient diagnosed with Stage
1 of the
disease has a 90 per cent chance
of surviving for five years, while
a
patient with Stage 2 has a 70 per
cent chance of survival. This figure
goes down to 30 per cent for Stage
3 and 10 per cent for Stage 4,
so it is
imperative that we try to catch
the disease in its early stages.
 Dr Andrew Khoo,
consultant plastic and aesthetic
surgeon, Aesthetic & Reconstructive
Centre, a member of Pacific
Healthcare, says: 'One
of the
recent advances in breast cancer
surgery is what is known as a skin
sparing mastectomy. In this procedure,
the purpose is to remove the tumour
while retaining as much of the
breast skin as possible. Breast
skin is
best for a reconstruction because
it has the most natural appearance
and
it has sensation unlike skin imported
from elsewhere in the body.'
Nine out of 10
patients who see Dr Khoo for breast
reconstruction
are
cancer patients. Given the strain
they have been under, Dr Khoo
makes sure
they are fully briefed about
the reconstruction options.
Dr Khoo says: 'From the point
of view of treating the cancer,
the
mastectomy probably has to be
done and the patient does not
have much
choice there. But when it comes
to reconstruction I tell patients
they
have five options - firstly,
they can choose not to do a reconstruction
at
all; secondly, they can opt for
implants. The third and fourth
options
involve a reconstruction using
a skin flap from the back or
using a slice
of skin and fat from the lower
abdomen. Finally, they can delay
their reconstruction until they
have fully completed their treatment.'
It is comforting
to know that even when there is
no reconstruction,
there
are ways of giving the appearance
of a breast, using an external
prosthesis that is worn in
the bra.
The second option of having
a breast reconstructed from
implants
involves
inserting implants under the
patient's breast skin that
has been saved
during the skin-sparing mastectomy.
According to Dr Khoo, the implants
used in a reconstruction are teardrop
shaped, to reflect
the natural
shape
of the breast; implants are
made from silicon gel or saline
or
a
combination of gel and saline.
The third choice
in breast reconstruction options
is to
use a flap of skin
from the latissimus dorsi,
a muscle from the patient's
back,
to form
a new
breast. Breast reconstruction
using skin and fat from the lower
abdomen
is known
as a TRAM flap, short for
Transverse Rectus Abdominis
Myocutaneous
flap.
Says Dr Khoo: 'In a TRAM
flap, we take a transverse
slice
of skin and fat from
the lower abdomen and shape
this into a new
breast
for the
patient.
In my experience, the TRAM
flap gives the softest
and most natural
breast
reconstruction because
the breast has size and
volume
or what we
call
ptosis, which is how the
breast falls naturally
when the patient
is
upright. If a patient has
fuller breasts that are
ptotic or
naturally
droopy, then the TRAM flap
gives more leeway for sculpting
a new
breast,
with aesthetically better
results.' The
downside of a TRAM flap is that
the procedure
involves
a
second
operative site and a
recovery period of six
to eight
weeks, compared
to
the two-week period for
implants.
In the fifth option,
patients go through
the entire healing
process
of
surgery, chemotherapy
and radiotherapy before
breast
reconstruction.
There
are, however, disadvantages
to delaying reconstruction,
says
Dr Khoo. 'I
don't really encourage
a delayed reconstruction
because
studies
indicate
an overwhelming advantage
in proceeding with
the reconstruction
immediately. The number
one reason for this
is that it
gives the
best
results aesthetically
now that surgeons can
save
the breast
skin. Also psychologically
there is no trauma
- the
reconstruction is performed
immediately after the
mastectomy so the patient
goes in
for a mastectomy
and comes out with
a new breast.'
The reconstruction
methods favoured
by Dr Khoo's
patients are implants
and
the TRAM. Dr Khoo
says: 'Ultimately,
the reconstruction
route
each patient
takes is a combination
of her needs, the
shape and
size of
her breasts
and
the type of breast
cancer she has. We
usually check
if the
patient
requires radiation.
The impact of radiation
is
mostly on
implants so it is
not a good idea to
put an implant in
and go
for radiation.'
One question
that troubles patients
is whether
the reconstruction
will
affect their chances
of surviving cancer.
Dr Khoo
has reassuring
data:
'Studies clearly
show that up to
Stage 2
of breast
cancer, reconstruction
has no bearing
at all on survival
and
disease
recurrence.
Unfortunately,
there is insufficient
data to make the
same assertion
for the
more
advanced stages.'
Copyright © 2005
Singapore Press Holdings Ltd. All
rights reserved.
Source:
Business Times, 29 September 2006 |
